1. Field of the Invention
The present invention relates generally to a blood pressure measuring apparatus, and more particularly to the blood pressure measuring apparatus of the type in which a bag-like belt or band wound around an arm of a person is automatically pressurized.
2. Description of the Prior Art
Heretofore, there is known a blood pressure measuring apparatus in which the bag-like belt or band attached to a person whose blood pressure is to be measured is pressurized by means of a pressurizing pump, and subsequently the pressure within the bag-like band is detected by means of a pressure sensor while the pressure within the band is concurrently decreased at a reduced rate through a show discharge value. On the other hand, the Korotokov's sound (hereinafter, also referred to simply as K's sound) is detected by using a K's sound sensor. The output signals of both sensors are processed by a microcomputer to derive the maximum and minimum values of the blood pressure which are then visually displayed.
In the blood measuring apparatus of the type described above, it is known that the pressurization of the bag-like belt or band is performed automatically up to a preset pressure value or level. The pressure value must of course be higher than the expected maximum pressure value as measured. It is also empirically known that when the set pressure value is excessively high, difficulty may be encountered in attaching the accurate measurement.
However, the maximum blood pressure becomes different in dependence on the individuals whose blood pressures are to be measured. Correspondingly, the present pressure level must be correspondingly different. Accordingly, in case the setting of the pressure level before the measurement is forgotten or confirmation of the set pressure level is left neglected before the pressurization, there may happen such situation in which the pressurization of the arm compressing belt is insufficient for measuring the blood pressure of a given person with an acceptable accuracy. In that case, the compressed air within the bag-like belt must be discharged once and the pressurization has to be again performed. In the hitherto known blood pressure measuring apparatus, the set pressure value preset by the pressure setting device is simply displayed in the form of numerals or marks, involving thus a problem that the set pressure valve is left unconfirmed or not altered to a proper set value.